OnlineMedEd: Obstetrics - "3rd Trimester Labs"

Question 1

List the five diseases that you should screen for in the 20-28 week period.

Answer 1

• Preeclampsia (covered in a different video)
• Gestational hypertension (also covered in a different video)
• Gestational diabetes
• Alloimmunization
• Maternal anemia

Question 2

Interestingly, which lab should you NOT use in diagnosing gestational diabetes?

Answer 2

A1c

Question 3

Which test was the old lab used in diagnosing gestational diabetes?

Answer 3

2-hr GTT

Question 4

Above ________ is a positive GTT.

Answer 4

140

Question 5

Explain how the 3-hr GTT is done.

Answer 5

You take a fasting glucose and then a 1-hr, 2-hr, and 3-hr glucose after a 100 g bolus of glucose. Any two of the following is a positive screen: 
• Fasting greater than 90
•1-hr greater than 180
•2-hr greater than 155
•3-hr greater than 140

Question 6

Although oral meds are given for gestational diabetes in real life, ________ is the most studied and supported treatment.

Answer 6

insulin

Question 7

Only mothers who are __________ can develop alloimmunization.

Answer 7

Rh-negative

Question 8

When should you administer RhoGAM to an Rh-negative mother?

Answer 8

At 28 weeks and then again within 72 hours of delivery

Question 9

What test can reveal fetal anemia?

Answer 9

Transcranial doppler (which would show increased flow if the fetus is anemic)

Question 10

Hemoglobin reaches its lowest point at which week of pregnancy?

Answer 10

28 (usually dropping as low as 10)

Question 11

If the Hgb is lower than 10 at 28 weeks, then you should order _____________.

Answer 11

iron studies